Ken Nakayama: Subjective Contours
Talk by Ken Nakayama, Department of Psychology, Harvard University. Given to the Redwood Center for Theoretical Neuroscience at UC Berkeley. Note: many of the demo's required wearing using special stero glasses, with red and green colored filters. The green colored filter goes over the right eye.
Audio/Visual sound, color
The concept of the receptive field in visual science has been transformative. It fueled great discoveries of the second half of the 20th C, providing the dominant understanding of how the visual system works at its early stages. Its reign has been extended to the field of object recognition where in the form of a linear classifier, it provides a framework to understand visual object recognition (DiCarlo and Cox, 2007). Untamed, however, are areas of visual perception, now more or less ignored, dubbed variously as the 2.5 D sketch, mid-level vision, surface representations. Here, neurons with their receptive fields seem unable to bridge the gap, to supply us with even a plausible speculative framework to understand amodal completion, subjective contours and other surface phenomena. Correspondingly, these areas have become backwater, ignored, leapt over. Subjective contours, however, remain as vivid as ever, even more so. Everyday, our visual system makes countless visual inferences as to the layout of the world surfaces and objects. What’s remarkable is that subjective contours visibly reveal these inferences.